Pantograph.



. PATBNTED MAR. 31, 1903.,

M. BARR. PANTOGRAPH.

APPLICATION FIPBD AUG. 14, 1899.

8 SHEETS-SHEET 1.

N0 MODEL.

"Qui m.

No. 723,978. PATBNTBD. MAR; 31; 190s.

' M. BARR.

PANTOGRAPH.

APPLICATION IIKLBD AUG. 14, 1899.

NO MODEL. 3 SHEETS-SHEET 2.

'mi alims PETERS co. moro-urna., WASHINGTON. nv cv 'No.723,978. PATBNTED MAR. 31, 1903.

M. BARR. PANTOGRAPH.

APPLICATION FILED AUG. 14, 189.9.

1I()- MODEL. 8 SHEETS-SHEET 3.

m: Noam: paens co. pHoro-mmc. wAsmNTnN, u. c.

' UNITED STATES-r PATENT OFFICE.

` MARK BARR, OF BROADHEATH, ENGLAND, ASSIGNOR TO THE LINOTYPE COMPANY, LTD., OF LONDON, ENGLAND.

PANTOGRAPH.

srEcIFioAirIoN forming part of Letters Patek@ No. 723,978, dated March 31, 1903. Application tiled August 14', 1899. Serial No. 727|l37. (No modeLl To all whom zit-'may concern: Y

Be it known that I, MARK BARR, of Broad heath, in the county of Ohester,England,have

invented certain new and useful Improvepertains to make and use the same.

The present invention relates to improvements in pantographs and is specially applicable to pantograph engraving-machines.

Referring to the accompanying figures, which are to be taken as part of this specification and read therewith, Figure l is a plan;

Fig. 2, a front elevation corresponding therewith Figs. 3 and 4, details on the same scale; Fig. 5, a detailed front elevation, on an enlarged scale, of the free endof the rigid bar v'and its support; Fig. 6, a detail rear elevaf tion of the same, and Fig. 7 a plan corre' Isponding with Fig. 5.

'a is the base-plate, and Ab is a bridge-piece standing upon the base-plate a, to which it is securely bolted, as shown at Ic c. It serves principally to furnish a vertical bearing d llior the spindle c. The bottom end of this l'spindle turns in a foot-bearing f, which is 'carried by a stirrup g, made fast to the under side of the base-plate ct. The top of the spindle 'e stands up above the bearing el for some distance for a purpose which is explained farther on.

'7L is Ea lever having its fulcrum in the spindle e. It is pivotedby its opposite end to the respective end of a link t' at z. The other end of this link t' is pivoted on an offsetj, projecting from one end of a swinging bar This bar k is straight and rigid throughout its length. an antifriction-roller device Z l', &c., which is carried by a horizontal bracket m, springing from a boss n, which rests upon the baseplate a and turns about the spindle e. 0 is an arm turning by one end about the said spindle. Its outer end is not connected to `any member of the pantograph.

p is a link pivoted by its respective ends to the arm o and to the link 'i on the axes z z2. This link p is always parallel with the lever h from every point of view.

Its opposite end is supported by' The lever lz, the bar lo, the arm 0, and the links v." and p together constitute the pantograph of the present invention, and the spindle e is the center on and about which it works. Theunited weight of the parts h, k, o, t', and 1o is supported by tie rods q q, stretched from the collars q' q', loose upon the top of the spindle e between two collars q2 qfast thereon, to an' eye g3 upon the lever h, close to the outer end of it, and to a post g4, standing up from the outer end of the arm o, as shown in Fig. 2. The tie-rods q q and the upstanding top of the spindle e are not included in Fig. l.

The link t' is adjustable in respect of its length in the same way as the lever h andthe link p, as indicated at The pivot-blocks p2 p3 of the link p are adjustable lengthwise of the arm o and the link t', respectively, by means of screws o t2, turning in slots vo2 .t3 without longitudinal advance and about axes alined with the said arm and link,respectively. r is the tracer. It is carried by the offset j,with its axis coincident with the pivotal connection between the link i and that offset.

s is the quill that receives the engravingtool. vIt revolves in a blocks', adjustable in a slot s2, lengthwise of the link. The block s" stands on the sam-e side of the swinging bar k as does the offsetj, and the axes of the tracer 1', of the quills, and ofthe spindle e are always alined with each other. `Thedistance Qfrom thepantograph center e to the axis z', that from the said axis z to the axis of the quill, and that from the axis a' to the axis z2 are always equal. The adj ustability of each is for variations in the ratio of reduction.

o.' is thetable for the pattern over which the tracer r is moved, and a2 is the table for the work.

The swinging bar la is X-shaped in crosssection, the four webs being ofY equal dimensions and the four internal angles right angles. :Two of the webs, 7c lo', are vertical and two, 4k2 k2, horizontal. The engraving or other tool is held to the bar lo by a device through which ythe said bar can slide to and fro in the direc-v IOO s3 S4 are two lugs fast to the block s', already described, and from which they project at about a right angle with each other toward the bar 7c and as far as its opposite side, as shown in Fig. 1.

S5 is a horizontal bar pivoted midway of its length on the lug S3 by a vertical pivot S11.

.s6 is a vertical pivot in one end of the bar and carrying a horizontal roller S7 on each side of the adjacent horizontal web 7a2. S8 is a similar pivot at the other end of the same bar, carrying two rollers s1 likewise. The rollers sT S7 are to bear against one side of the vertical webs 7c 7o of the .bar 7c, while the rollers ss S11 are to bear against the opposite side of the same webs.

3111 (see Fig. 4) is a flange on the bar $5, and S12 is a set-screw working through it against the lng s3 to set the two pairs of rollers .s7 .S7 and S8 S8 up to the bar 7.3.

S13 is a second horizontal bar, pivoted at one end on the lug s4 by a vertical pivot 311. 315 is a vertical pivot in the opposite end of the bar S13 and carrying a horizontal roller s16 on each side of the adjacent horizontal web 7a2, to bear against the same side of the vertical webs 7c k as the two rollers S7, above described. Thus the two outer pairs of rollers s7 s7 and S16 S16 bear against one side of the bar k, while the intermediate pair s1 s1 bears against the opposite side.

S11 is a set-screw working through a flange on the bar S13 and against the lug s4, between the pivots S11 and S15, to set the pair of rollers s1 .S111 up to the respective webs 7c 7s in the same way as the set-screw 312 sets up the pair S7 S7.

The antifxictionioller device ZZ', dsc., already mentioned as constituting a supporting device for the end of the bar 7s opposite to the tracer r and through which the said end can move freely to and fro in the direction of its length is of the same type as that just described for holding the tool-holding block s' and bar 7c together. The rollers of it, however, bear upon the horizontal Webs k2 7a2 of the bar 7c, as well as upon the vertical webs 7a' 7a'.

Z'1 is a bar pivoted midway of its length on a horizontal pivot Z5, carried by the end of the bracket m, already described.

Z2 is a horizontal pivot in one end of the bar Z1 and carrying a vertical roller Z on each side of the top web 7c. 73 is a similar pivot in the other end of the bar Z4 and likewise carrying a vertical roller Z on each side of the bottom web 7c. The rollers Z Z are to bear down upon the top and the rollers Z' Z' up against the bottom faces of the horizontal webs 7.:2 7a2.

m is a set-screw working through a projection m1 on the bracket on and against the bar Z1, between the pivots Z3 and Z5, to set the two pairs of rollers Z Z and Z Z up to the respective faces o-f the horizontal webs 7a2 k2.

Z111 is a second and horizontal bar pivoted midway of its length on a vertical pivot Z25, carried by a lug Z211, fast on the bracket m.

Z9 is a vertical pivot in one end of the bar Z10 and carrying a horizontaLroller Z8 on each side of the said bar Z111. Z111 is a similar pivot at the other end of the same bar, carrying two rollers Z11 Z11 likewise. The rollers Z8 Z8 are to bear against one side of the vertical webs 7c 7c', and the rollers Z11Z11are to bear against the opposite sides of the same webs.

m3 is a set-screw working through a projection m1 on the bracket m and against the bar Z111, between the pivots Z25 and Z12, to set the two pairs of rollers ZS ZE1 Z11 Z11 up to the respective webs 7c 7.a'.

14 is a third bar pivoted at one end on a lug Z1 on the bracket m (see Fig. 3) by a pivotpin Z2?, which is held fast to the said lug Z111. Z15 is a vertical pivot in the opposite end of bar Z1A1 and carrying a horizontal roller Z17 on each side of the said bar to bear against the same side of the Vertical webs 7c 7s' as the pair of rollers Z8 ZS, already described.

m5 (see Fig. 3) is a set screw working through a projection m, fast on the pivotpin Z27 and against a flange m7 on the bar ZM, between the pivots Z15 and Z, to set the rollers Z17 Z17 up to the respective webs 7a 7a.

Z1S is a fourth bar, pivoted at one end on a horizontal pivot Z1, fast to the bracket m. Z2@ is a horizontal pivot in the opposite end of the said bar Z111 and carrying a vertical roller Z111 on each side thereof to bear against bottom faces of the horizontal webs 702 702. as do the rollers Z Z. m11 (see Figs. l and 2) is a setscrew working through a projection 'm9, fast 'on the bracket m and against the said bar Z15, between the pivots Z1 Z211, to set the pair of rollers Z21 Z21 up to the horizontal webs 7.52 762.

a3 is a rest fast upon one corner of the table a to receive the small diameter 1" of the tracer when the latter has to be changed.

The mechanism for rotating the quill s is as follows:

y is the first motion-pulley and loose upon `the spindle e. It is driven by a cord y'.

y2 is a second pulley fast to the pulley y.

ys is a pulley connected by a sleeve y1 to a pulley if. The sleeve is carried by a vertical post y, fast to the pivot-blockp8 of the link p.

gf( is the driving-cord around the pulleys y2 1/3, and ys the one around the pulley y and the quill-pulley y.

Heretofore the arm o has been of the same length as the link 1I, and the linkp has been connected to the outer ends of the said link 'Z and arm 0. According to the first part of the present invention the length of the arm o is reduced to about one-third and the connections of the link 19 to the said arm and linkt placed correspondingly nearer to the lever 7L, with the practical advantage that during the time the operator is at work his access to his work is not interfered with by any of the members of the pantograph system. The adjacent ends of the swinging bar 7c and the link t' are held together by being pivoted about the axis of the tracer r. Consequently the tracer makes every other mem- ICO IIO

ber of the pantograph move with it. Especially does it push the bar k before it through the device that holds the tool-block s to it and lche device that supports the opposite end of it, instead of leaving the end of theV said bar behind it to be in the operators way by overhanging the table a. The block s', that carries the engraving-tool quill, cannot bind in the slot s2, because the two links h and p are of the same length and must be always parallel with each other.

I claim- The hereinbefore-described combination in a pantograph, of rigid bar having the tracer fast to one end thereof and holding the tool and tracer alined with the center of the instrument; supporting device on which the other end of the said rod can move freely to and fro in the directionv of its length; lever pivoted by one end about the said center; short arm pivoted about the said center; link pivotedby one end on the outer end of the said lever and having its opposite end pivoted upon the tracer; link to carry the toolholding blook and pivoted by its ends to the short arm and link respectively near the said lever and always parallel with the latter; and tool-holdin g block held to the rigid bar above mentioned by a device permitting the said 

